Thelymitra petrophila (Granite Sun Orchid)

Thelymitra petrophila is a tuberous, perennial herb with a single erect, leathery, channelled, glaucous, light green linear to lance-shaped leaf 100–600 mm (4–20 in) long, 4–12 mm (0.2–0.5 in) wide. Between two and ten or more pale blue to mauve or pink flowers 20–30 mm (0.8–1 in) wide are arranged on a flowering stem 100–700 mm (4–30 in) tall. The sepals and petals are 10–15 mm (0.4–0.6 in) long and 3–8 mm (0.1–0.3 in) wide. The column is white to pale blue or pale pink, 5–7 mm (0.2–0.3 in) long and 2–4 mm (0.08–0.2 in) wide. The lobe on the top of the anther is brown to reddish or yellow with an inflated tube shape and wavy edges. The side lobes have toothbrush-like tufts of white hairs. Flowering occurs from August to November.

The granite sun orchid grows in shallow soil pockets on granite outcrops. It is found in the drier parts of Western Australia, including the Great Victoria Desert.